Burner for incandescent lamps.



0. M. THWLESS. BURNER FOB INCANDESCENT LAMPS. (Lpplieltion led. July 23! 1896. Renewed Feb. 17, 1899.) (No Miodel.)

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UNITED STATES PATENT OFFICE.

ORLANDO M. THOWLESS, OE NEWARK, NEI/V JERSEY.

BURNER FOR INCANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 633,350, dated September 19, 1899. Application filed July 23, 1896. Renewed February 17, 1899. Serial No. 705,858. (No model To all whom it may concern.-

Be it known that I, ORLANDO M. THOW- LESS, a subject of the Queen of Great Britain, and a resident of Newark, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Burners for Incandescent Lamps, of which the following is a specification.

My invention relates to incandescent lamps and burners for the same in which a thin strip of filament of highly-resisting material is caused to glow or incandesce by reason of the heat developed when a current of electricity is forced through said burner or lament. Hitherto such burners or filaments have been made of solid strips of carbon or other highly-resistant materials, and in some lamps metallic burners have been used. Hollow carbon-tube burners have also been employed. These lamps have, however, generally been of low efficiency and in most instances short-lived.

The object of my invention is to furnish a burner or filament which while being cheaply constructed is very eflicient-that is, requiring few watts of energy per candle=power-and is more durable than any other with which I am acquainted.

The globe, the sealing, the exhaustion, the leadingain Wires are the same as are generally employed in lamps of the incandescent class and require no further description.

To carry my invention into effect, I can proceed in various ways, which I will now describe.

The accompanying drawings Ishow the geni eral plan of my burner in its various forms. The burner is shown partly in section and partly in elevation.

ternal or basic filament; Fig. 2, a hollow non- .conducting base Without the internal filament, and Fig. 3 shows the non-conducting base as solid.

Referring to Eig. 1, A represents a burner composed of the internal filament B, the nonc'onducting base O, and the coating or deposited surface D.

Fig. 2 shows a burner A', composed of the hollow non-conducting base O and the lightvgiving coating D.

` Fig. 3 shows the burner A2, composed of the solid non-conducting base C2, coated by the light-giving surface D2.

I take an ordinary incandescent lamp filament or burner or a metallic or composition Wire and cover it with a non-conductingsubstance. For this basic lament I prefer to take a combination of carbon and alumina., carbon and iron, carbon and manganese, carbon and tungsten, or a metal or metallic compound 0r oxid having the property of forming conductors. One method of producing this non-conducting covering. on the basic filament is to take, say, a cotton braid, soak it in a proper saltfor instance, nitrate of alu mina-and apply itto the above-mem tioned filament or burner. The burner thus covered is submitted to a high degree of heat, electric or otherwise, and the result is the destruction of the cotton covering, leaving ailament or burner covered with a so-called non coducting material. (The word non-conducting is used in this specification in its usual electrical meaningthat is, a comparatively poor conductor). In order to deposit upon the non-conducting covering a layer of conducting material, the burner is thensubjected to the 'process known in the art as iiashing. This is done by placing the burner 'thus prepared in the flashing jar or apparatus' and exhausting the air from the same. When the air in the apparatus has reached the requiredl degree of exhaustion, the air-pump is shut off and the flashing apparatus is filled with a hydrocarbon or other suitable gas. An electric current isthen sent through the burner and the same is raised to a high degree of temperature, when the carbon from the gas begins to deposit upon Figure 1 shows the burner having an inthe burner, and this operation is continued until the desired homogeneity and the required resistance of the burner is secured. After this has been accom plis-hed the original or basic filament or substratum may be either removed by pulling it out, or chemically, or by burning it out with a heavy current, or by any other of thewell-known methods. This removing of the substratum is not, however, absolutely necessary, as it may remain and assist in giving rigidity to the burner. I can, of course, also perform the dashing operation IOO by innnersing` the burner in a heavy hydrol carbon oil and heating it by means of an electric current.

'lhere are other methods besides using cotton braid saturated with the appropriate salt by which I may secure the non-conducting material upon which the cond noting-surface is deposited or coated. For instance, I may make a paste ot the non-conducting material and apply it to the basic filament b v means of a brush, or I may apply it chemically or by electric or igneous fusion or otherwise. The conducting-envelop ofthe burner may be simply drawn on over the non-conducting basic filament, like a hood, and be mechanically and electrically independent of the non-con'- ducting portion, the latter serving merely to give shape and stability to the light-giving portion. In this construction the materials for the light-giving portion, the non-conduct ing basic lilament, and the method of their treatment remain the same.

As materials for forming the non-conducting portion of the burner I have tried and recommend the nitrate, the sulfate, the chlorid, and the silicate of alumina, magnesia, and other similar substances whose salts when properly treated form a highly-resistant material. There are certain substances that I can use which under the combined reducing effect of heat and carbon may form carbids which, although comparatively poor conductors, would still be better conductors than some of the materials mentioned for the nonconducting covering. Stich carbid-forming substances are, for instance, zirconium, thori um, calcium, silicon, and others. Although these carbids would not be so efficient as the layer of non-conducting material mentioned above, yet in some cases they mayanswer the purpose o f the non-conducting covering.

Instead of using deposited carbon as the light-giving material I may deposit other substances answering the same purpose, for instance, metallic deposits, as metallic zirconium, niobium, molybdenum, or silicon; also, besides carbids mentioned above, some metallic oxids, as well as other materials that form conductors and are capable of being deposited or coated on the non-conducting base.

As I have said above, it is not necessary to remove the basic filament, but when it is left in order to give stability to the burner it does not form the light-givingportion of the burner, the electrical connection being made to the material deposited or coated upon the non-conducting portion ot the burner.

In order to prepare the non-conducting base for receiving the carbon deposit in the flashing-jar when no internal filament is employed, I proceed as follows: I pour oil of rosemary on dry chlorid of platinum in a porcelain dish and knead it until all parts of it are well moistened. I then rub this up with tive times its weight of oil of lavender and allowit to stand a short time in order to clear.

The lilamentary strips are thinly coated with the above preparation and afterward heated in a muftle or over a Bumsen burner. This gives a coating of platinum to the surface ol the filament, which can then be'placed in the hydrocarbon flashing-jar and carbon deposited thereon to the proper thickness.

For high-voltage lamps in which a very high resistance is necessary, I may employ for the light-giving portion (deposited or coated) a conducting substance combined or mixed with a non-conducting or poorly-conducting one. For instance, a proper mixture of carbon and magnesia or of carbon and a carbid may be deposited or coated upon the non-conducting portion of the burner and serve as the light-giving substance.

My invention is not limited in its scope to a strip or filamentary form, but may be applied to burners of any desired shape or size. For instance, the burners may have the form ot a mantle or hood, such as is usual in the Telsbach or Auer gas-burner, or it may be button-shaped or in the form of a thin ribbon.

Vhat I claim isl. A burner for incandescent or glowlamps composed of an internal basic lilament or strip covered with a layer of non-conducting material and a light-givingsurface deposited thereon.

2. A burner for an incandescent lamp composed of a basic non-conducting tilament having a loosely-fitting conducting-covering, designed to serve as the light-giving portion of the burner.

3. The method of making burners for incandescent lamps, which consists in properly preparing the surface of an internal non-conducting core, solid or hollow, for receiving a layer of electrically-deposited carbon, and then submitting the burner so prepared to the action of the dashing or other similar process.

4. A burner for incandescent lamps, consisting of a hollow tube or cylinder of nonconducting substance covered with a layer of conducting material.

5. A burner for incandescent lamps, composed of a hollow internal ilament or strip, a coating of non-conducting substance, and a layer thereon of conducting material.

6. A burner for incandescent lamps composed of a properly-prepared non-conducting base, and having for its light-giving portion a composite material composed of a mixture of conducting and poorly-conducting substances.

7. A burner for incandescent lamps, composed of an internal filament, a layer of nonconducting substance, and a covering of comfposite conducting material.

8. A burner for incandescent lamps, composed of a hollow non-conducting base covered with a layer of composite material formed of a mixture of conducting and non-conducting substances.

9. A burner for incandescent lamps hav- IOO IIO

f ing a properly-prepared internal non-conducting base, upon which is deposited or coated. a light-giving portion of metallic carbid.

10. A burner for incandescent lamps, having a properly-prepared internal non-conducting core, and whose light-giving portion is composed of conducting metallic oxids.

11. The method of making burners for incandescent lamps, which consists in treating a chlorid of platinum with proper essential oils,applying the resultant compound to a nonconducting basic iilament, heating the filament thus covered,vand subjecting the fila-v ment thus formed to the action of an electric current in the presence of a hydrocarbon gas or liquid. l

In testimony that I claim the foregoing as my invention I have signed my name in presence of two Witnesses.

ORLANDO M. THOVLESS.

Witnesses:

ADAM FRANK, JNO. J. FLYNN. 

